Peppermint is a flowering plant that grows throughout Europe and North America with a long history of use for digestive conditions.

Peppermint oil has been used historically for numerous health conditions, including irritable bowel syndrome and indigestion. It is also often used for digestive problems in children.

Peppermint is also commonly used in the food and drug industries for its scent, flavor, and cooling and soothing properties. Other possible applications include using peppermint as a muscle relaxant during certain medical procedures and for soothing symptoms associated with respiratory infection and difficulty breathing.

Peppermint oil is available as bulk herb oil, capsules, and in liquid form. The United States is a major producer of peppermint, and the largest markets for peppermint oil are manufacturers of chewing gum, toothpaste, mouthwash, and drugs.

Peppermint is generally believed to be safe in healthy, non-allergic adults in doses often found in foods.

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

GRADE *

Based on a variety of studies, the use of peppermint to improve irritable bowel syndrome (IBS) symptoms is currently supported.

A

Peppermint oil has been proposed as a possible treatment to prevent muscle spasms. It has been applied to the stomach lining to prevent muscle contraction during a medical procedure used to look inside the esophagus, stomach, and small intestine. Additional research is needed in this area.

B

Early evidence suggests using peppermint daily may help prevent cracked nipples, reduce pain, and increase duration and number of feeds during breastfeeding. Additional research is needed in this area.

B

Application of peppermint oil or menthol solution to the forehead and temples may be an effective treatment for headache. However, additional research is needed before a firm conclusion can be made.

B

Early evidence suggests that a combination of peppermint oil and caraway oil may be beneficial for heartburn symptoms. Further high-quality studies are needed.

B

There is currently a lack of evidence to draw a firm conclusion regarding the use of peppermint oil for stomach swelling.

C

Early research suggests that cleaning the mouth with a mixture of diluted tea tree oil, peppermint oil, and lemon oil may improve bad breath in intensive care unit patients. However, studies examining peppermint alone are needed.

C

There is insufficient research on the use of peppermint in the treatment or prevention of the common cold. Additional studies using peppermint alone are needed.

C

There is insufficient evidence regarding the use of peppermint for dental plaque and gum inflammation. Additional research using peppermint alone is needed.

C

A mouth rinse containing peppermint oil reduced teeth staining; however, the effects on bacterial counts were lacking. Additional research using peppermint alone is needed.

C

There is insufficient evidence regarding the use of peppermint for hot flashes. Additional research using peppermint alone is needed.

C

There is currently insufficient evidence regarding the use of peppermint for itching. Further research using peppermint alone is needed in this area.

C

Although early research is promising, there is currently a lack of sufficient evidence on the use of peppermint oil affecting alertness following brain injuries. Further research is needed before a conclusion may be made.

C

Peppermint oil reduced the occurrence of nausea. It has also been reported to relieve nausea and vomiting during pregnancy. Additional research is needed before a conclusion can be made.

C

In early study, peppermint aroma has shown mixed effects on cognition, attention, and alertness. Additional research is required before a firm conclusion can be made.

C

There is currently insufficient evidence to determine if there are benefits of peppermint oil in the treatment of nerve pain that occurs following a shingles infection. More high quality studies are needed in this area.

C

There is insufficient evidence to assess the possible benefit of peppermint oil in the treatment of postoperative nausea. More high quality studies are needed in this area.

C

Peppermint oil has been found to reduce the pain children experience during irritable bowel syndrome (IBS) as well as recurring stomach pain. Peppermint has also been found to reduce stomach pain and swelling following the surgical removal of the appendix in other people. Additional studies are needed in this area.

C

There is currently insufficient evidence regarding the use of peppermint for stress. Further research using peppermint alone is needed in this area.

C

Early studies suggest that aromatherapy with acupressure may reduce shoulder pain in people recovering from strokes. However, the effect of peppermint oil cannot be determined from these findings due to the use of acupressure and other oils at the same time. Additional studies using peppermint oil alone are needed.

C

Peppermint oil has been traditionally inhaled to relieve congestion in the nose and lungs. While some early evidence suggests that inhalation of peppermint oil may be beneficial in the treatment of tuberculosis, additional high-quality research is needed before a firm conclusion can be made.

C

Peppermint tea added to other therapies has been used in the treatment of urinary tract infections. It is not clear if this is an effective treatment. Additional studies using peppermint oil alone are needed.

C

* Key to grades

A: Strong scientific evidence for this useB: Good scientific evidence for this useC: Unclear scientific evidence for this useD: Fair scientific evidence for this use (it may not work)F: Strong scientific evidence against this use (it likley does not work)

Tradition / Theory
The below uses are based on tradition, scientific theories, or limited research. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. There may be other proposed uses that are not listed below.

For the prevention of muscle spasms, five drops of peppermint oil in 10 milliliters water has been taken by mouth. Colpermin® capsules containing 187 milligrams or 0.2 milliliters of peppermint oil has been taken by mouth four hours before medical examination of the colon. As a spray, 20 milliliters of peppermint oil in concentrations from 0.4-1.6% has been applied to a body cavity during a medical procedure for up to 165 seconds. Solutions containing 8-40 milliliters of peppermint oil have been infused into the intestine during medical procedures and to treat colon spasms.

For digestive disorders, 0.2-0.4 milliliters of peppermint oil in dilute suspensions have been taken by mouth.

For indigestion, two capsules of peppermint oil have been taken by mouth three times daily for five days following an operation. A single dose of 0.2 milliliters of peppermint oil in water has been taken by mouth before a meal.

For irritable bowel syndrome, peppermint has been taken by mouth in doses of 187-500 milligrams or as 0.2 milliliters of liquid 1-4 times daily for up to four weeks. Peppermint has been taken by mouth for 2-8 weeks or three times daily for six weeks. One or two 0.2 milliliter capsules have been taken by mouth 2-3 times daily before or with meals for 2-3 weeks. People with severe symptoms have taken six capsules by mouth daily. Colpermin® capsules containing 187 milligrams or 0.2 milliliters of peppermint oil has been taken by mouth 3-4 times daily 15-30 minutes before meals for up to eight weeks. Peppermint oil (180-200 milligrams) capsules have been taken by mouth 30 minutes before a meal. Mintoil® capsules containing 225 milligrams of peppermint oil have been taken by mouth twice daily for four weeks. Following a test meal, 0.64 milliliters of peppermint oil has been taken by mouth after fasting overnight. Three peppermint oil capsules have been taken by mouth daily for four weeks.

For sore throat, lozenges containing 2-10 milligrams of peppermint oil have been taken by mouth as needed.

For nausea and vomiting, 3-6 grams of peppermint leaf and a 5-15 gram tincture have been taken by mouth. Gauze pads containing 0.2 milliliters of peppermint oil, peppermint oil in a bottle or inhaler, and Aromastick (combination of peppermint and lemon) have been inhaled.

For various stomach, intestinal, gall bladder, and bile duct conditions, 2-4 grams of dried herb extract has been taken by mouth three times daily. An infusion of 1.5-3 grams of peppermint oil in 150 milliliters of water has been taken by mouth three times daily. One milliliter, containing 10% oil and 1% leaf extract, with water has been taken by mouth. As a tea, 3-4 cups daily of 3 grams of peppermint leaves in 250 milliliters of water has been taken by mouth between meals. As a tincture (1:5 preparation), 2-3 milliliters has been taken by mouth three times daily.

For stomach swelling, 0.5-1 milliliters of peppermint oil in 2 liters of hot water soaked on a towel has been placed on top of the stomach for 20-30 minutes three times daily.

For breast tenderness, peppermint gel and a peppermint water-soaked cotton has been applied to the nipples for 14 days.

For headaches, one milliliter of 10% menthol solution or 10% peppermint oil has been applied to the skin (forehead and temples) at the start of a headache and repeated 15-30 minutes later.

For nerve pain occurring after shingles, peppermint oil (2-4 drops; standardized to 10% menthol) has been massaged into the skin 3-4 times daily.

For cough, 3 milliliters of a menthol solution has been inhaled by people undergoing medical examination of the lungs. Menthol 75% in eucalyptus oil has been inhaled every hour for five hours.

For nasal congestion, 3-4 drops of oil in hot water has been inhaled as needed. Menthol 62.5 milligrams in petrolatum has been applied and inhaled.

For mental performance enhancement, 4 drops of oil applied to a pad has been placed inside a work cubicle and inhaled. In a surgical mask, 20 microliters of peppermint has been inhaled in a single 10 minute dose and two 15 minute doses.

For postoperative nausea, three breaths of a gauze pad soaked with peppermint oil have been inhaled. Vapors from a bottle of peppermint oil have been inhaled when needed. Three deep inhalations of one milliliter peppermint spirits has been used in up to three doses five minutes apart.

Children (younger than 18 years)

For irritable bowel syndrome in children 8-10 years old, 0.1-0.2 milliliters of Colpemin® (containing 187 milligrams of peppermint) has been taken by mouth three times daily for two weeks.

Avoid applying peppermint oil around the facial or chest areas of infants and young children, especially around the nose.

Safety
The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.

Allergies

Avoid in people with known allergy or sensitivity to peppermint, its parts, or members of its plant family.

Allergic reactions may occur from using peppermint or menthol by mouth or on the skin, including throat closing, breathing problems, skin rash, hives, or skin irritation caused by contact.

Peppermint oil is likely safe in small doses (up to 270 milligrams peppermint oil), in the form of tea, and when taken by mouth in amounts commonly found in foods.

Peppermint is possibly safe when taken by mouth or applied to the skin and for medicinal reasons. Peppermint oil capsules appear to be safe when used under medical supervision in children eight years and older.

Peppermint may interfere with the way the body processes certain drugs using the liver's "cytochrome P450" enzyme system.

Peppermint may lower blood sugar levels. Caution is advised in people with diabetes or hypoglycemia, and in those taking drugs, herbs, or supplements that affect blood sugar. Blood glucose levels may need to be monitored by a qualified healthcare professional, including a pharmacist, and medication adjustments may be necessary.

Peppermint may interfere with the way the body processes certain drugs using the liver's "cytochrome P450" enzyme system. As a result, the levels of these drugs may be altered in the blood, and may cause potentially serious adverse reactions. People using any medications should check the package insert, and speak with a qualified healthcare professional, including a pharmacist, about possible interactions.

Peppermint may lower blood sugar levels. Caution is advised when using medications that may also lower blood sugar. People taking drugs for diabetes by mouth or insulin should be monitored closely by a qualified healthcare professional, including a pharmacist. Medication adjustments may be necessary.

Peppermint may interfere with the way the body processes certain herbs or supplements using the liver's "cytochrome P450" enzyme system. As a result, the levels of these herbs or supplements may be altered in the blood, and may cause potentially serious adverse reactions. It may also alter the effects that other herbs or supplements possibly have on the P450 system.

Peppermint may cause low blood pressure. Caution is advised in people taking herbs or supplements that lower blood pressure.

Peppermint may lower blood sugar levels. Caution is advised when using herbs or supplements that may also lower blood sugar. Blood glucose levels may require monitoring, and doses may need adjustment.

Peppermint may also interact with Alzheimer's herbs and supplements, antacids, antianxiety herbs and supplements, antibacterials, anticancer herbs and supplements, antifungals, antihistamines, anti-inflammatory herbs and supplements, antioxidants, antiparasitics, antiulcer and stomach acid-reducing herbs and supplements, antiviral herbs and supplements, basil, caffeine-containing herbs and supplements, herbs and supplements for osteoporosis, herbs and supplements for the heart, herbs and supplements that affect the nervous system, herbs and supplements for the stomach and intestines, herbs and supplements that are toxic to the liver, herbs and supplements that expel phlegm from the lungs, herbs and supplements that improve mental performance, herbs and supplements that prevent muscle spasms, herbs and supplements that protect against radiation damage, herbs and supplements that suppress cough, herbs and supplements that suppress the immune system, herbs and supplements that treat abnormal heart rhythms, herbs and supplements that treat nausea and vomiting, hormonal herbs and supplements, insect repellants, iron, pain relievers, perillyl alcohol-containing herbs and supplements, quercetin, salicylate-containing herbs and supplements, and vitamin D.

The information in this monograph is intended for informational purposes only, and is meant to help users better understand health concerns. Information is based on review of scientific research data, historical practice patterns, and clinical experience. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions.